Device for clamping plates together with impervious jointing



y 1962 F. A. H. SANTERRE 3,036,673

DEVICE FOR CLAMPING PLATES TOGETHER WITH IMPERVIOUS JOINTING 2Sheets-Sheet 1 Filed Oct. 20, 1959 JNVENTOR. Fernond Adrien HenriSunterre BY i621.

LLD- 7 20 c (5 ATTORNEY y 9, 1962 F. A. H. SANTERRE 3,036,673

DEVICE FOR CLAMPING PLATES TOGETHER WITH IMPERVIOUS JOINTING Filed 001;.20, 1959 2 Sheets-Sheet 2 INVENTOR. Fernond Adrien Henri SonterreATTORNEY United States Patent 3,936,673 DEVlCE FQR CLAMPHNG PLATESTOGETHER WITH IMPERVIOUS J OINTING Fernand Adrien Henri Santerre, Rueil,Seine et (Eise,

France, assignor to La Telernecanique Eieetrique,

Nanterre, France Filed Get. 20, 1959, Ser. No. 847,530 Claims priority,application France Oct. 29, 1958 7 Claims. (Cl. 189-36) The presentinvention is particularly, but not exclusively, directed to a closuremeans for metal panels of electric control boards or boxes to be clampedabout a resilient joint-seal to render said boards or boxes waterand/ordust-proof.

It is known that the imperviousness of such boxes is generally achievedby clamping the cover onto a jointseal which can be of rubber, tallowedbraid or of plastic material inserted between said cover and theassociated flange of the box.

The technical problem is to exert an adequate clamping stress at spacedpoints on the cover edge, without however entirely crushing theresilient joint-seal which would otherwise rapidly deteriorate or crackand would lose its impervious properties.

In known constuctions, the cover is pressed by cam members or screwspivotally mounted on hinges welded onto the outside of the box, but thissolution to the problem is tedious and closing the device is a long andcomplicated procedure.

According to a further known construction, the inner edges of the boxeshave lugs provided with tapped holes welded thereto, screws extendingthrough the cover to be clamped registering with the tapped holes in thelugs. However, such an arrangement meets with certain difficulties; thecover must be suitably centered on the opening for the jointseal to becorrectly compressed by the cover and the screw holes must be accuratelyaligned with the axes of the tapped holes in the lug, this not beingeasy to achieve when there are numerous holes and in repetitive work.

Imperviousness must also be maintained at the holes provided in thecover for the passage of the screws, this requirement being usuallyafforded by means of washers of deformable metal, such as lead, placedunder the screw head. Lastly, the screws extending through the cover aregenerally additionally provided with a device of the so-called safetytype in order that the said screws will be held captive when the covermember is removed.

This device complicates the construction and is not always effective.

The object of the present invention is to provide a solution to thetriple problem of compensating for the inaccuracies in boring, ofensuring imperviousness and of holding the screws captive to one of theplates.

The present invention concerns a device adapted to clamp two plates toone another, and more specifically to clamp a cover onto an iron box,with a joint-seal inserted there between, of the type in which a screw,mounted on the cover member in such a manner as to prevent it from beingmisaligned, is threaded into a corresponding tapped hole which is boredin the box, and is able to be slightly displaced with respect to thelatter.

It comprises essentially a base plate fixed on one face of the box edge,a floating nut, means for securing the floating nut onto the base plate,while leaving a certain amount of play to the nut, a partlyscrew-threaded and partly plain-shanked pin with a guiding end, capableof being threaded into the floating nut, and a cup-shaped washer ofresilient material, inserted into a hole formed in the cover member,said cup-shaped washer providing a seating for the head of said threadedpin and comprising means to effect a seal with the threaded pin on theone hand, and with the cover member on the other hand.

Other features and advantages of the present invention will become clearon reading the following description, with reference to the accompanyingdrawings, showing one embodiment of the invention. In these drawings:

FIGURE 1 is a perspective view, partly in section, of a box providedwith the devices of the invention;

FIGURE 2 is an exploded perspective view of the various components ofone of said devices;

FIGURE 3 is the plan of the floating nut;

FIGURE 4 is the plan of an auxiliary element;

FIGURE 5 is a section on a larger scale of the sealing washer; and

FIGURE 6 is the plan of a box with the cover removed.

In the embodiment shown, the device in accordance with the inventionpermits the closing of an electric control box '1 by a panel 2, aresilient joint-seal 3 being inserted therebetween.

This device comprises a threaded pin 4 which is threaded at 4a andreceived in a floating nut 5.

The threaded pin 4 has a countersink head 6 and a conical tip 7 forcentering. The portion 8 of the shank adjacent to the head and abovethreaded portion 4a is unthreaded.

The floating nut is advantageously cross-shaped. It comprises two shortlegs 9 and 1t and two long legs 11 and 12 perpendicular to the shortlegs. The short leg 10 is bent at The two long legs 11 and 12 are eachpierced by a circular or elongated hole 13. The second short leg 9 issubstantially in the same plane as the two long legs 11 and 12.

The floating nut 5 has a certain freedom of movement in a planeperpendicular to the threaded pin 4. This movement is confined by prongs14 of an element 15 welded on the inside of the flange 16 of the box.This plate-like member 15 can be placed in a corner at an angle of thebox or parallel to the edges thereof when clampings are required along acertain length of the sheet (FIG- URES 1 and 6). In order to enable theplate 15 to be positioned in a corner of the box, the angles of saidplate which would have interfered with the positioning are cut ofl topresent a pair of chamtered edges 17 and 18.

In general, the plate =15 is U-shaped. The tongues or prongs 14perpendicular to the plate are provided on the inner edge of the legs 19and 20 of the U-shaped member. The space existing between said legs 19and 20 enables the threaded pin 4 to pass through into the centraltapped hole 21 in the floating nut 5.

Prongs 14 of plate 15 extend through the holes 13 of said floating nutand are then bent outwards.

The threaded pin 4 passes through a washer 22, whereby the clamping areais sealed and the threaded pin cannot by m-islaid. This washer is formedof a sufficiently resilient material, such as plastic, rubber or thelike. It comprises a flared cup-shaped portion 23 which acts as a seatfor the countersink of the screw head 6. The washer 22 is held captiveto the sheet metal panel 2. through which it passes, by means of anouter retaining head 24 with which it is provided. The washer is furtherprovided with an inner retention collar 25.

The closing of the box by means of the clamping devices in accordancewith the invention is carried out as follows:

Plate-members 15 are welded to the inside of flange 16 of the box atlocations where clampings are desired to be elfected.

The floating nuts 5 are slid onto the prongs 14 of the plates 15 andthese prongs are folded down without being clamped, so as to leave thepermitted freedom of movement to the nuts.

The cover panel 2 is bored with counter-sunk holes for the passage ofthe screws, so that these holes are as far as possible in alignment withthe tapped holes 21 in the floating nuts 5.

The cup-shaped washers 22 are then threaded or forcefitted onto thescrews 4, so that the inner collars 25 of the washers are at leastengaged into the threads 4a of the screws. Upon being provided withtheir respective washers, the screws are inserted into the holes boredin the cover panel. These washers 22 then abut, by a bevelled edge 24aof their outer beads 24, the countersunk portion of the holes bored inthe panel.

The next step is to screw the threaded pins 4 perpendicularly to thebox. In the course of this screwing step, the boring inaccuracies aretaken up, the sealing effect is achieved and the screws are safe-guardedfrom being lost in the case of removal of the panel;

The conical tips 7 of the screws centre themselves in the tapped holes21 of the floating nut 5 which, by virtue of their relative mobility,automatically take up the boring inaccuracies;

The countersink heads 6 of the screws are clamped against the seatingsprovided by the flared portion 23 of washers 22, and the retentioncollars 2-5 of said washers penetrate to the unthreaded shank portion 8of the screws, unless they have been positioned there earlier, so that adouble sealing effect is achieved;

The outer beads 24 of washers 22 are forced into the holes bored in thecover panel and take up their initial shape again immediately uponpassing therethrough. Thus the screw-Washer assemblies cannot bemislaid.

The screws are tightened up to a moderate clamping stress, the limit ofthe squeeze-clamping of the joint-seal 3 being controlled by the bentleg 10 of the cross-shaped nuts 5 which acts as a stop.

It is to be understood that the above description has been given merelyby way of explanation, without any intent of limitation, and thatvarious modifications can be made therein without falling outside thescope of the invention.

Thus, according to one embodiment, the prongs or tongues 14 can be madeintegral with the flange 16 of the box or be cut from said flange.

I claim:

1. A joint assembly comprising two juxtaposed members, one of saidmembers including an aperture portion, the other of said membersincluding an edge portion spaced from said aperture portion, a baseplate on the other of said members, a floating nut, means for securingthe floating nut onto said base plate, said base plate and nut includingportions affording relative lateral movement therebetween, a partlyscrew-threaded headed pin with a guiding end threaded in said floatingnut and a resilient washer circumposed about said pin and retained insaid aperture portion of said one member, said washer including aportion providing a seat for the head and said threaded pin andeffecting a seal thereabout with said one member, the base plate and nutportions comprising two tongues integral with said baseplate anddisposed on opposite sides of a portion forming a notched portion insaid base plate, said nut including two aperture portions freelyreceiving said tongues therethrough.

2. A joint assembly comprising two juxtaposed members, one of saidmembers including an aperture portion, the other of said membersincluding an edge portion spaced from said aperture portion, a baseplate on the other of said members, a floating nut, means for securingthe floating nut onto said base plate, said base plate and nut includingportions alfording relative lateral movement therebetween, a partlyscrew-threaded headed pin with a guiding end threaded in said floatingnut, and a resilient washer circumposed about said pin and retained insaid aperture portion of said one member, said washer including aportion providing a seat for the head of said threaded pin and effectinga seal thereabout with said one member, said threaded pin including acountersink head, said washer comprising a conical portion receivingsaid countersink head, said washer includes an annular projection on aninner base portion thereof grippingly engaging the shank beneath saidhead.

3. A device according to claim 2 wherein said washer includes twocircumferentially spaced beads formed at an outer portion of said washerand sealingly disposed about opposite sides of said one member at theaperture portion thereof.

4. A device according to claim 3, wherein said washer includes abevelled lower edge portion to facilitate the positioning thereof in theaperture portion of said one member.

5. A device according to claim 1, wherein said floating nut iscross-shaped and includes two opposed coplanar legs each including oneof said apertured portions.

6. A joint assembly comprising two juxtaposed members, one of saidmembers including an aperture portion, the other of said membersincluding an edge portion spaced from said aperture portion, a baseplate on the other of said members, a floating nut, means for securingthe floating nut onto said base plate, said base plate and nut includingportions affording relative lateral movement therebetween, a partlyscrew-threaded headed pin with a guiding end threaded in said floatingnut and a resilient washer circumposed about said pin and retained insaid aperture portion of said one member, said washer including aportion providing a seat for the head and said threaded pin andeffecting a seal thereabout with said one member, a joint seal betweensaid members, said nut including an abutment portion engaged with anunder surface portion of said one member for preventing an excessivecrushing pressure to be imposed on said joint seal.

7. A joint assembly comprising two juxtaposed members, one of saidmembers including an aperture portion, the other of said membersincluding an edge portion spaced from said aperture portion, a baseplate on said other member, a floating nut disposed beneath said baseplate and including a vertically extending abutment portion extendingbeyond said base plate and engageable with the under surface of the oneof said members, and a threaded fastener extending through the apertureportion of the one of said members and threadedly engaged with saidfloating nut for drawing the same toward the one of said members inclamped relationship with respect to the other of said members and thebase plate thereon, said base plate including fastening means dependingtherefrom and engaged with said floating nut for retaining the floatingnut in secured relationship to said base plate.

References Cited in the file of this patent UNITED STATES PATENTS2,172,248 Kost Sept. 5, 1939 2,632,538 Schmidt Mar. 24, 1953 2,647,004Stieglitz July 28, 1953 2,684,515 Zahodiakin July 27, 1954 2,905,287Kawecki Sept. 22, 1959 FOREIGN PATENTS 190,482 Great Britain June 7,1923 81,821 Sweden Oct. 23, 1934 93,934 Sweden Dec. 28, 1938

